"So it just takes a lot of photos while ramping through the focus from close to infinity" — right, but not "close to infinity". It grabs focus on what it can see, and that's it. So if your scene is simple, i.e. a close up of one or two objects, the ramp and therefore video is very fast. If you have a large distance between subjects, then it records a longer video.
It actually works surprisingly well on moving subjects like flowers in the wind (not so much on kids running around). I've produced a video for Panasonic that should be online any moment now, where I show the flowers bit, as well as a bee buzzing around. Kinda cool.
You can't specify points of focus, no. It uses all points available to grab focus on everything it can. It doesn't just rack through though… if you have an two objects with a gap between them, it doesn't focus on the nothing in-between. It simply jumps from one object to the other. And yes it only works in 4K Photo mode, 8.2 MP.
It does not work in RAW, since it's shooting 4K Photo (which is 4K video in a 4:3 aspect ratio), so you get an M4V file and extract JPEGs from that (in-camera or on a computer).